Adoption rates of electronic health record (EHR) systems and pay-for-performance (P4P) programs have been increasing and now these two innovations have merged, as the Center for Medicare and Medicaid Services (CMS) has started to permit the use of EHR data for measuring quality in their P4P measures.1,11,12,23,24 While literature exists on the challenges of using claims and registry data for P4P programs, there is little guidance on how to use EHR data for quality reporting. 2-8 Few studies have explored the validity of using EHR data to identify a target population or studied specifically how using EHR data can impact quality measures.5-8 In addition, there is little information on the accuracy and consistency of EHR data, specifically how physicians use the EHR data to store information about patient diagnoses.9-10 Despite this lack of information, P4P programs are expanding their use of EHR data.1 This is a particular concern given that P4P programs that are perceived to be inaccurate by physicians may ultimately damage the credibility of P4P programs that actually improve the quality of patient care. Our study proposes to evaluate the validity of using EHR data in P4P measures, specifically focusing on quality measures in diabetes, one of the conditions for which CMS permits the use of EHR data. We plan to evaluate the validity of different approaches to using EHR data (i.e., different combinations of EHR data elements) in identifying patients with diabetes by comparing these EHR approaches to a gold standard manual medical record review. We will then determine how different approaches to using EHR data impact quality measures, specifically how these approaches impact the proportion of patients who meet quality standards. Finally, we will gain a better understanding of the reliability of EHR data by learning how physicians document diagnoses in the EHR and what motivates their documentation behaviors, through one-on-one interviews with primary care physicians. The findings will provide guidance, currently unavailable, as to how to best leverage existing EHR data for monitoring healthcare quality. PUBLIC HEALTH RELEVANCE: Administrators of pay-for-performance programs (P4P) that have traditionally used claims data for quality measures have started to permit the use of data from electronic health records (EHRs). However, there is very little understanding about the methods of using EHR data for quality purposes, and inaccurate or biased quality measures can seriously undermine the credibility of valuable quality improvement initiatives. This project will evaluate the validity of using EHR data for quality measures, providing critical information to administrators of quality improvement program as they move towards using EHR data.